Blade engageable electric connector



July 14, 1953 5. s. FORTINO 2,645,750

BLADE ENGAGEABLE ELECTRIC CONNECTOR Filed May 31, 1951 'rigi.

INVENTO SFIMVEL FQRTIAIG BY q Patented July 14, 1 953 npanann GEABIZE iriLEcrRIo;

F Q N B r Samuel- 823 FontinopNew York, .Yi'. assigg ontop Electric-i Mamllacturing:l Company,

' Innafimok lmiNsl, a corporation! of New York- Ap ne non Margit, 1951, Serial No. 229,225

1-75 v This invention relates to: at bladeengag'eable electric connector; that "is to :sayyanelecttic pone nectorwhichis provided'witlr contacts thafare It invariably has, been the practice heretofore to provide each contactiofi'a .blade engageable' cord, connectoiiwith an attachedjstiif terminal piece for connection tea cord; Althbughlsuch connectors are made inhuge quantities so'that it is desirable to. simplify-their,gconstructiongand manufacture in all respects,- and;a1thpugh1 it is recognized that a particularly desirable osimplia; fication would .bethe elimination) of the stiff, ter minalpiece, until the present. invention such' sime plification hasnot. beenvachie'ved because the very resiliencev which was needed to enable-athewcom tacts. to properly function as -ocontactsl madelit and arrangementslof partsswhicliwill. besexemplii fied :in the devices =hereinafterdescribed andsof; which the scope: of fapplication :will be indicated invtheappendedclaims.

Inth'e accompanying drawings incwhich are shown' various possibleembodiments: of: my

impossible to form a.us able terminal;in.onelpiece with .the contact, anduthis samemresili'encesplez vented such a terminal from actingas affirm sup; port relativeitowhich thercontact legslcouldlfi'x. It is anHobjectofmyinvention'tcprovid an improved. blade engageablee electric: connector. having one piece terminal-contactslwhich arenot subject to the foregoing drawbacks? Morespecificallmit is, an object ofimy inviention to provide in a blade engageable.electrioconnecs tor a terminal-contact having inonerpiece theres' tures; iofsconstructiong .combinationssoirielements invention; I I i Fig; liis. a; perspective view of arone pieccfiters minal-contact embodying my invention; the same being-illustrated before: connection to a cordq Fig. 211s a-viewsimil'ar to Fig; 1,".butish'ovving th'e'terminal-contact after connection toa cordf- Fig; 3 is an enlarged sectional view takensubstantially along the line 3I-3 of Fig. 2, and addi- 1 tionally illustrating theoperative; portion-of upper crimp-ing 'die which engages: th'epart of th'e terminal-contact show-n'in section:

Fig. 4 is an enlarged sectionalviewtaken sub stantially alongthe=line 4'4 of F i'g'r2, and addi tionally illustrating the operativeportion-'ofthe upper crimpin die -which engagesth'e part of theterminal-contact shown -in-" secti'on;

Fig: 5 is a plan view of a-multiple -cord='-connector incorporatingterminal contacts embodying my invention; one-half-of the-'b'Ody'being removed better to show the location of said com tacts'; and I Fig; 6 1s air'agmentary view similar to Fig-.71 showing a -modified-'- form of terminal-contact embodying-my invention;

Referring now in-detai1 to the drawings;:' and moreyparticularly t o Figs: 1 through -5j the'ref erence numeral I0 denotes a terminal contact' constructed in accordance -with'-my inventionand consisting" of but" a single "piece; of ;sheet *metal. Thispmetal is electrically; conductive and isiof springy stock in order {to impart to the terminalcontact therequisite resilience. In addition; the metal is somewhat ductile; A typical satisfactory metal-is red brass, this having agcompositiongof about copper and 15% zinc. Anotherrtypical metal with .which'good results are securediscommercial 'bronze.,c onsisting of about l%.-" copper andj10% zinc.. The sheet stocklfr'om Jwh'ich'thie terminal-contact is made preferably'i s about 0.02 inch thick.

The terminal-contact" I 0 is blanked "from such sheet stack and formed in suitable machinery;-

well known to-the art; to-theshape indicatedin F'ig. 1. At this stage"the-=-terminal=contact*in cludes a plurality of=wide-contact-iegsl2, l4;- l6 whose shape and =rela'tive positions are conven r tional. By way=of-example,-'thethree contact legs form a Tifof which the legs -l 2; l8 are the'cross bar and the leg l t the upright. Eiieh lg is proevided with a dimple I 8 near its base and is bowed away from said dimple adjacent the tip of the leg. The foregoing arrangement and construction is conventional.

Pursuant to my invention the terminal-contact further includes a shank 20 which extends away from the cross bar and is located opposite the le 14. Said shank is broader than the leg [4 and is coplanar with the bases of the three legs. The tip 22 of the shank is angularly ofiset in the same direction that the legs are bowed, the ofiset preferably being disposed at substantially a right angle to the plane of the shank. Intermediate the tip of the shank and the point where the shank is joined to the cross bar, the body of the shank is formed with two pairs fingers 24, 26, 28, 3D.

One pair of fingers 24, 26 is located on one as well as desilient, I am able to crimp the cord engaging fingers without fracturing the same and can force the fingers into tight engagement with the sheath and stranded conductor without having the fingers back oil from the cord after the crimping operation. With the fingers in cord engaging position, said fingers and the cord serve to stiffen the shank of the contact and thus provide a comparatively firm base relative to which the contact legs can be flexed. Moreover because the fingers of each pair are immediately juxtaposed they provide mutual reinforcement for each other, further stiffening the shank n-andqtending to retain the crimped fingers in of upstanding edge of the shank and the other pair of fingers 28, 30 is located on the opposite edge. One finger of each pair, e. g. the inner finger 24, is transversely registered with one finger of the opposite pair, e. g. the inner finger 28', and the remaining two outer fingers 26, 30 likewise are transversely registered. The fingers of each pair are in immediate juxtaposition, that is to say, said fingers are separated by a slit rather than a slot so that the fingers have their adjacent edges in rubbing contact. At the stage that the contact is ready to have a wire connected thereto, this being the condition shown in Fig. 1, the two pairs of fingers extend vertically awa from the body of the shank in the same direction as the dimples. Said fingers maybe formed sim-' ply by striking the same from the shank with suitable tools thereby leaving notches 32, 34.

A standard electric cord 36 of a type adapted to be secured to the terminal-contact in constitutes a stranded wire conductor 38 encased in an insulating sheath 4%. To secure the cord to the terminal-contact the insulating sheath is stripped off the end of the cord so as to bare the end 42 of the stranded conductor. The cord is laid between the two pairs of fingers with the bare end 42 pointing toward the contact leg I4, and with the end of the sheath between the outer fingers 26, 30 and close to the slits separating the outer fingers from the inner fingers. Thereupon the two pairs of fingers are crimped about the cord. The crimping die includes an upper portion 44 which forces the outer fingers 26, 30 into a semi-circular shape which, in conjunction with the shank, defines a tight loop constrictively embracing the sheath 40. The crimping die further includes another upper portion 46 which forces the inner fingers '24, 28 into engagement with the bare end of the stranded conductor. Said inner fingers are so crimped that their tips 48 are directed downwardly toward the shank whereby said fingers, in conjunction with the shank, roughly define an hourglass, that is to say, a loop whose center is narrower than its ends. Due to this arrangement, the tips of the inner fingers are forced into the bare end of the stranded conductor, separating the strands and making an excellent electrical connection. The outer fingers 2G, 30, by tightly gripping the sheath, make an excellent physical connection with the cord thereby serving as a strain relief.

The crimping tool includes a lower half or anvil, not shown, of suitable contour to impart the illustrated shape to the shank.

- It should be noted that by selecting a sheet metal stock such as described which is ductiled their cord engaging position.

A pair of terminal-contacts embodying my invention and connected to the ends of a duplex cord are shown in Fig. 5 as they appear when incorporated in a multiple cord connector including a body consisting of two halves 49, only one of which is illustrated, the other being removed so that the terminal-contacts better can be seen. It will be observed that each of the three contact legs when engaged by a blade is arranged to flex relative to the shank 20 and that the offset tip 22 of said shank functions to keep the terminal-contacts spaced apart properly and to prevent the terminal-contacts from rattling.

A terminal-contact 50 embodying a modified form of my invention is shown in Fig. 6. Said contact difiers from the terminal-contact ID in that it is provided with a sharp tine 52 in its shank 54 between two pairs of fingers 56, 58, 60, 62 located on'opposite edges of the shank. Said fingers, like the fingers of the terminal-contact I0 are transversely registered.

In the use of the terminal-contact 50 the insulating sheath is not stripped from the stranded electric conductor. The electric cord simply is placed between the two pairs of fingers and the fingers are clinched about the cord in the manner that the fingers 26, 30 are clinched about the cord 36. Desirably the inner fingers 58, 6O first are clinched and then the outer fingers 56, 62. This serves to locate the conductor positively with respect to the terminal-contact, before the fingers 56, 62 are clinched thereby en suring that the tine 52 will pierce the insulating sheath and become embedded in the stranded wire conductor.

Although my invention has been illustrated in connection with a terminal contact having three legs it will be understood that the invention is not so limited and that any number of legs, one or more, may be used. Likewise it will be appreciated that the immediately juxtaposed transversely registered pairs of fingers, in addition to being used for engaging a cord such as described, may be employed for engaging other conventional electrical elements such for example as the shanks of prong blades.

It thus will be seen that I have provided devices which achieve all the objects of my invention and are well adapted to meet the conditions of practical use.

As various possible embodiments might be made of the above invention, and as various changes might be made in the embodiments above set forth, it is to be understood that all matter herein described, or shown in the accompanying drawings, is to be interpreted as illustrative and not in a limiting sense.

Having thus described my invention, I claim as new and desire to secure by Letters Patent:

1. A terminal-contact for use in a blade engageable connector, said terminal-contact comprising a single piece of ductile resilient sheet metal stock including an entirely fiat, fiexible, contact leg and a shank, said shank having on one edge thereof a pair of fingers whose adjacent fingers :are in rubbing engagement and on the opposite edge thereof another pair of fingers Whose adjacent fingers are in rubbing engagement, said pairs of fingers being transversely registered and being adapted to be crimped on an electrical element for engagement therewith, said fingers serving to stiffen the shank whereby to firm the same so as to act as a, base relative to which the contact leg can flex.

2. In combination an electric cord constituting a stranded wire conductor and an insulating sheath, the bare tip of said conductor extending beyond the end of the sheath, and a terminalcontact for use in a blade engageable connector, said terminal-contact.comprising a single piece of ductile resilient sheet metal stock including an entirely fiat, flexible, contact leg and a shank, said shank having on one edge thereof a pair of immediately juxtaposed fingers and on the opposite edge thereof another pair of immediately juxtaposed fingers, said fingers being transversely registered,

' one pair of fingers being crimped on the bare tip of the conductor and the other pair of fingers being crimped on the sheath adjacent its end, said fingers serving to stiffen the shank whereby to firm the same so as to act as a base resilient to which the contact leg can flex.

3. A combination as set forth in claim 2 wherein the fingers which are crimped on the sheath are formed to a semi-circular shape and the fingers which are crimped on the conductor have their ends directed towards the shank and embedded in the conduct-or.

SAMUEL S. FORTINO.

References Cited in the file of this patent UNITED STATES PATENTS 

